The present invention is generally directed to a stereoscope for helping an observer to combine the images of two 2-dimensional photographs taken from two points of view to obtain the effect of depth
The development of stereoscopes has had a long history. One of the first stereoscopes did not require mirrors or prisms. The stereoscope was a box which had an aperture for each eye and a single aperture on the opposite side. The observer had to cross his or her eyes in order to perceive the two pictures as a single picture. This made stereoscopic viewing very difficult and resulted in considerable eye strain. Later stereoscopes employed various combinations of mirrors and lenses for viewing pictures taken with stereo cameras. The typical stereo camera has two lenses which are spaced 2.5 inches apart, which is the same spacing as for the average adult human eyes and takes two pictures at the same time. This close lense spacing limits the stereo effect to a relatively short distance. One recent stereo camera employs four lenses and prints are produced which do not require the use of a separate stereoscope. However, the quality of the pictures are not good because of a special plastic grating, (a flat stereoscope) which must be placed on the prints and the cost of print processing is considerably higher than for ordinary 35 mm. prints.
Conventional stereo viewers include lenses which cause the eyes to focus at infinity with no inward rotation. The pictures to be viewed are placed left and right. In order to see the stereograph, the pictures must be placed at a precise distance from the lenses. The position of the pictures must be adjusted for individual variations and eye spacing. Conventional stereoscopes are relatively complex optical devices which require adjustments for variations in eye spacing. These and other difficulties experienced with prior art stereoscopes have been obviated by the present invention.
It is, therefore, the principle object of the invention to provide a stereoscopic viewer for enabling an observer to obtain the effect of depth by combining images of two photographic prints taken sequentially from two points of view by a conventional camera, or at the same time from a pair of cameras.
Another object of this invention is the provision of a stereoscope which enables the observer to combine the images of two photographic prints and enables the observer to naturally converge and comfortably focus on the combined image at the normal distance for viewing photographs.
A further object of the present invention is the provision of a stereoscopic viewer which does not require any adjustment for variations in the eye spacing and which can be used by children and adults.
It is another object of the present invention to provide a stereoscopic viewer which can combine the images of two photographs of the same scene taken from two points of view by positioning one photograph above the other.
A still further object of the invention is the provision of a stereoscopic viewer which is simple in construction, easy to manufacture and relatively inexpensive.
Another object of the invention is to provide a stereoscopic viewer for photographs taken by a conventional camera which is easy to use and which does not require any additional equipment.
It is a further object of the invention to provide a stereoscopic viewer for pairs of pictures for 3D viewing which are generated by "conceptual" cameras such as with artwork which is produced by artists and designers and computers.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto.